Probiotics may improve metabolic health in adults with prediabetes Original paper

In this meta-analysis of randomized controlled trials, supplementation with probiotics improved some metabolic parameters in adults with prediabetes.

The effect of supplementation with probiotics on metabolic, anthropometric, and inflammatory parameters in the context of prediabetes.

Specifically, the following outcomes were studied:

• Biomarkers of glycemic control: HbA1c, fasting glucose, HOMA-IR, and insulin
• Blood lipids: Total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides
• Inflammatory biomarkers: tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)
• BMI

A total of 550 men and women (average ages of 38–55) with prediabetes.

A meta-analysis of 7 randomized controlled trials was performed. Two trials each were conducted in New Zealand, Japan, and Iran, and 1 trial was conducted in South Korea.

Five trials administered single-strain probiotics (Lactobacillus rhamnosus, Lactobacillus plantarum, or Lactobacillus casei) and 2 trials administered multi-strain probiotics (containing probiotics from the Lactobacillus, Bifidobacterium, and Streptococcus genera). The probiotics were administered in capsules, a mixing powder, yogurt, or milk. The comparator was a placebo (capsules, powder, yogurt, or milk) in all trials. The intervention duration ranged from 1 to 6 months.

Supplementation with probiotics reduced (improved) HbA1c (moderate effect size; moderate certainty) and HOMA-IR (small effect size; high certainty) and increased (improved) HDL cholesterol (large effect size; low certainty).

There is a discrepancy between the SMD value for HDL cholesterol in the abstract (which seems to be incorrect) and the value that appears in the forest plot (Figure 4a) and grading of evidence table (Table 3) in the full text. Here, we reported the latter.